Electric switch.



U. WOODS & W. H. SAYLES.

BLEGTRIO SWITCH.

APPLICATION FILED DEG-1B, 190a.

Patented Mar. 14, 1911.

mf'r essea' Cb/umas 77. 7 17727027117 Jay elf??? COLUMBUS WOODS ANDWHITMAN H. SAYLES, OF PEORIA, ILLINOIS.

ELECTRIC SWITCH.

Specification of Letters Patent.

Patented Mar. 14, 1911.

Application filed December 18, 1908. Serial No. 468,252.

To all whom it may concern:

Be it known that we, COLUMBUS Wooos and WHITMAN H. SAYLES, citizens ofthe United States, residing at Peoria, in the county of Peoria and Stateof Illinois, have invented certain new and useful Improvements inElectric Switches; and we do hereby declare that the following is afull, clear, and exact description of the 1nvention,.which will enableothers skilled in the art to which it appertains to make and use thesame.

This invention relates to improvements in electric switches particularlyof that type known as snap-switches.

Our switch is particularly designed for use at and operated by the doorof an electrically operated elevator-car or a car having an electricmotor as its driving means a switch being used at each door of theelevator-shaft and forming part of the motor-circuit and act ing tobreak said circuit, when a door is opened, so that the elevator-carcannot be operated so long as said door stands open or ajar. Saidswitch, however, isapplicable to other uses as well and consists incertain new and novel structures as will be clearly pointed out hereinaided by the accompanying drawing in which Figure 1 shows the interiorof our improved switch. Fig. 2 is a longitudinal section of a switcharm. Fig.3 is a plan of certain contact portions of the switch, and Fig.4 is an end elevation of the same.

A switch having a quick snap action for preventing as much as possiblethe forming of an are by the heavy current between the terminals is oneadvantage of the structure and operation of our improved device thusmaking it of value for many purposes important among which, however, isits use on electrically controlled elevator-cars, or

elevator-cars whose driving power is an electric motor the current forwhich is controlled by said switch through the movement of theelevator-door (not shown).

A suitable supporting base for the parts of the switch is provided andwhich, in this instance, is in the form of a containing case 7 toinclose the said arts. A plunger-rod or bolt P is mounted in said caseand in the present instance extends through the walls thereof which arebored to receive it, said plunger-rod for elevator use being disposedhorizontally and in one end is a stop S outside the wall of the case andwithin the latter the plunger carries a spring Q one end bearing againstthe wall of said case nearest to which is the said stop S, the saidspring be ing held under compression against said wall by a pin R,carried n the plunger or by some equivalent means thereon whereby saidspring constantly tends to hold the said plunger in a positive mannerwith one of its ends extending some distance outside the case as shownin Fig. 1, the said stop S serving to limit the outward movement.

Pivoted to the back wall of the casin f is an arm T by means, forexample, 0% a screw U which passes through the lower end of the arm, thesaid arm being placed sub .stantially at right angles to the plunger andadapted to have a short extent of movement on its pivot and limited inone of its directions of movement by striking the casing or somesuitable stop and limited in its other movement by passing into orbetween the electricterminals which said arm is adapted to connect andnow to be described.

7 indicates an insulating block secured to the rear wall of the casing fand having two terminals 9 secured thereon and kept insulated from oneanother. To each of these terminals is connected a wire from theelectric circuit in which the switch is placed.

The free end of the arm T as shown in section in Fig. 2 is'providedwitha contact I piece or button Vat each side both of which are electricallyconnected by a portion W but which are insulated from said arm. 4 is aspring attached in any good manner at one end to the plunger-rod P asfor example by means of an eye 5 made adjustable in said plunger-rod bymeans of a nut 6. The other end of the spring is attached to the arm asby means, for instance, of a post 3 on that member. In the position ofthe parts shown in Fig.

l the plunger-rod is at its outermost posi" tion due to the spreadinaction of spring Q. In consequence of this the lower end of the spring 4whose stationary position is either at one side or the other of thepivot U, in this instance lies at the left of the said pivot and hascarried the arm to and holds it positively in the position at the leftor away from and out of contact with the terminals 9. Said spring 4 isconstantly under tension and must, therefore, hold the arm positively ineither of its extreme positions since its lower end moves past the pivotU from-side to side. When, now, the plungerrod is pushed inward or tothe right against its spring Q, the lower end of. the spring 4 iscarried beyond the pivot and the arm is moved suddenly between the saidterminals 9.

A peculiarity in the construction of our switch F makes it imperativethat when used, for instance, at an elevator door to control a motorcircuit the door must be absolutely closed'since if it were ever ajarthe switch will remain open and also the circuit of which it is a part,2'. e. the spring 4 will not be carried beyond the pivot U where ;it canexert its pull on the arm to carry it between the terminals. This may beunderstood by observing that the plunger P when forced against thetension of the spring Q, is given nearly its entire extent of movementin carrying the lower end of the spring 4 to a position opposite thepivot at U on the arm T. A further very slight movement of the plungerbeyond this point then carries the end of the spring beyond the pivot.to a

point where the spring will be brought into position to draw upon thearm T and suddenly snap it between the contacts 9 to close the circuit.The spring in moving toward the pivot is put more and more under strainuntil having reached thepivot the strain is nearly at its maximum sothat as the pivot is passed the arm is snapped between the contacts 9and there remains as long as the plunger is held in the positiondescribed. It is to be observed, that the pivot of the arm-T ispreferably quite near the plunger P so that the point of connection ofthe spring 4with the plunger will be.

quite close to the pivot and preferably beneath it. The pull of saidspring is strongest when its lower end is nearest the pivot U,

for since that end moves in a straight line a and the post 3 of the armTmoves in an are described from said pivot U the greatest distancebetween said post and said lower end of the spring is when that endpasses beneath the pivot. The spring Q of the plungeris preferably quitestrong so that unless the latter is positively held in some way, as forinstance, by a latched door the force of the spring will cause theswitch to be opened and the door to be thrown open as well.

From what has been said it is now 'seen that besides being constructedso as to have a quick snap action to prevent arcing the switch demandspositive action on the part of the user when employed in connection withan elevator-door in order that for thatparticular purpose it will bepositive as to the results desired of it.

For other uses such as an ordinary cir cuit-closer for electric lightingcircuits and the like, with the spring Q eliminated the plunger-rod Pcan be still moved in either direction so as to snap the arm to eitherof its positions where it will remain since there said spring lying atthe will be no tendency on the part of the spring 4 to shift it, thepull of said spring being almost directly at right angles ,to the lineof movement of the said plunger-rod. the snap action being as positiveas before. If the point of connection of said spring and eye were toofar above the pivot U the arm would be properly held in its extremeposition when the plunger-rod occupies its limits of movement but theproper snap-action" would not take place.

Such changes may be made in our device as will fall within the meaningof-the invention and scope of the claims.

Having thus described our invention, we claim 1. An electric switchconsisting of a single pivoted arm adapted to have a free arcuatemovement on its pivot, electric terminals in the path of movement of thearm at one of the extremes of "that movement, a member movable in a linesubstantially parallel to the chord of the are described by said arm,and acontractile member connecting. the arm and said member.

' 2. An electric switch consisting of a single pivoted arm adapted tohave a free arcuate movement on its pivot, electric terminals in thepath of movement of the arm at one of the extremes of that movement, amember movable ina line substantially parallel to the chord of the aredescribed by said arm, and a contractile member connecting the arm andsaid member to swing said arm, the

pivot of the latter lying substantially midway between the extremes ofits movements, the point of connection of the contractile member withthe first described member lying beneath the arm in either of its saidextremes of movement. 7

3. An electric switch consistin of a single rigid arm pivoted at one endan adapted to have a free arcuate movement on its pivot and to have twoextremes of positions, electric terminals at one of the extremes ofmovement of the arm to receive said arm, a member movable in a linesubstantially parallel to the chord of the are described by said arm,both the arm and the member, both ends of same side of a line extendingthrough the fpivot of the arm and the middle position 0 said arm whenthe said. arm is in either of its extreme positions.

4. An electric switch consisting of a single armpivotally supported atone endand adapted to have a free arcuate movement on its pivot to twoextreme positions, electric terminals in the path of movement of the armat one of its extreme positions, a member movable in a linesubstantially parallel to the chord of the are described by said arm, acontractile member connecting the arm and said member to swing said arm,the pivot of the latter lying substantially mida contractile springconnected toway between the extremes of its movement, the point ofconnection of the said contractile member with the first describedmember lying beneath the arm in either of its said extremes of movement,and means to yieldingly control the first said member.

5. An electric switch comprising a support, a single rigid arm pivotedthereto and having a free arcuate movement and having two extremes ofmovement, electric terminals in the path of movement of said arm at oneof said extremes of movement, a member carried on the support andmovable substantially parallel to the chord of the are described by saidarm, a contractile member connected between the arm and the first namedmember to swing said arm, the pivot of the latter lying substantiallymidway between the extremes of its movement, the point of connection ofthe contractile memher with the first described member lying beneath thearm in either of its said extremes of movement.

6. An electric switch comprising a support, a single rigid arm pivotedthereto and having a free arcuate movement and having two extremes ofsuch movement, electric terminals in the path of movement of said arm atone of such extremes, a member carried on the support and movablesubstantially parallel to the chord of the are described by said arm,means normally tending to yieldingly hold said member in one of itsextreme positions, a contractile member connected between the arm andthe first named member to swing said arm, the pivot of the latter lyingsubstantially midway between the extremes of its movement, the point ofconnection of the contractile member with the first described memberlying beneath the arm in either of its said extremes of movement.

7. In an electric switch,the combination of a casing, a single rigid armpivoted therein and adapted to have an arcuate movement on its pivot andhaving two extremes of position, a plunger rod carried in and normallyextending partially outside said casing and adapted for movement in aline substantially parallel to the chord of the are described by saidarm in its movement, a contractile spring attached to the arm andconnected to the said plunger rod at a position at one side of the pivotof said arm, said plunger rod when pushed inward carrying the end of thespring to the opposite side of the pivot whereby the arm is snapped fromone of its extreme positions to the other, electric terminals connectedby said arm in one of its positions, and means normally tending to holdthe plunger rod in its outward or extended position.

In testimony whereof we affix our signatures, in presence of twowitnesses.

COLUMBUS WOODS. WHITMAN H. SAYLES. Witnesses:

AUGUSTA BURKHARDT, L. M. THURLOW.

